In 1 megabytes there are 1.00000e-9 petabytes. Meanwhile in 1 petabytes there are 1,000,000,000 megabytes. Keep reading to learn more about each unit of measure and how they are calculated. Or just use the Petabytes to Megabytes calculator above to convert any number.
* Values rounded to 6 decimal places for readability
To convert megabytes to petabytes (MB to PB), you need to know which system your numbers use. Storage labels often use the decimal (SI) system, while many computers report sizes in the binary (IEC) system.
Decimal (SI) units (base-10)
Binary (IEC) units (base-2)
Tip: If you see sizes based on 1,024 steps (KB, MB, GB), you’re likely in binary. If it’s based on 1,000 steps, it’s decimal.
A petabyte (PB) equals 1,000,000,000 megabytes (MB) in the decimal system (base-10). This is the system most storage makers use on drive labels.
In the binary system (base-2), 1 pebibyte (PiB) equals 1,073,741,824 MB. That difference comes from how computers count bytes.
PB (petabyte) uses base-10 math:
PiB (pebibyte) uses base-2 math:
Operating systems often report storage closer to base-2, even when the label uses base-10.
No. They look similar, but they don’t match.
When you convert up to very large units like petabytes, that small gap becomes a big number.
It depends on the counting system.
Storage labels often use base-10. Many computer readouts use base-2.
Use one of these formulas, based on the unit system you need:
Write down which system you’re using so your totals stay consistent.
In decimal units:
That’s because 1 PB equals 1,000,000,000 MB, so one million MB is one-thousandth of a petabyte.
In decimal units:
So 1,000 terabytes is one petabyte, or one billion megabytes (decimal).
Drive makers usually use decimal units (1 TB = 1,000 GB). Many operating systems use binary units (1 TiB = 1,024 GiB), even if they display “TB” or “GB.”
That mismatch makes the shown number look smaller. The drive isn’t missing space; it’s being measured with a different ruler.
A pebibyte (PiB) is bigger than a petabyte (PB).
In bytes, 1 PiB is about 12.59% larger than 1 PB.
For most everyday file sizes and drive labels, 1 PB = 1,000,000,000 MB (decimal). For system memory and some technical tools, binary units may appear, where 1 PiB = 1,073,741,824 MB.
If you’re comparing numbers from two sources, match the unit system first.
The Calculate Box tool to convert megabytes to petabytes uses the open source script Convert.js to convert units of measurement. To use this tool, simply type a megabytes value in the box and have it instantly converted to petabytes.